Pencil sharpener



March 28, 1939.

H. w; JENKINS PENCIL SHARPENER Filed Jan. 26, 1957 INVENTOR ATTORNEYSZ0- N WITNESS 4 Patented Mar. 28, 1939 UNITED STATES PATENT OFFICE 1Claim.

This invention relates to pencil sharpeners and has for an object toprovide a pencil sharpener including a grinding wheel having a concaveperiphery and a holder adapted to position the pencil tangentially andcentrally on the concave periphery of the grinding wheel so that theresultant sharpened point will be a surface generated by a movingarcuate line passing through a fixed vertex instead of the ordinaryconical surface to the end that more wood will exist at the lead thanexists where the usual sharpened conical point is made and thus the leadwill be reinforced at its juncture with the wood to a greater extentthan hitherto possible.

A further object is to provide a pencil sharpener of this type in whichthe parts will be concealed in a transparent casing so that the grindingoperation may be clearly seen, there being a guard carried by the casingto prevent the sawdust following the wheel in the direction of rotation.

A further object is to provide a pencil sharpener of this type having avertically adjustable pencil holder to position the pencil relatively tothe grinding wheel so that the sharpened point may be a long keen pointor a stub point and also to allow adjustment of the holder to compensatefor any possible wear on the wheel.

With the above and other objects in View the invention consists ofcertain novel details of construction and combinations of partshereinafter fully described and claimed, it being understood thatvarious modifications may be resorted to within the scope of theappended claim without departing from the spirit or sacrificing any ofthe advantages of the invention.

In the accompanying drawing forming part of this specification,

Figure 1 is a plan view of a pencil sharpener constructed in accordancewith the invention.

Figure 2 is a front elevation of the pencil sharpener shown in Figure 1.

Figure 3 is an end elevation of the pencil sharpener with parts brokenaway.

Referring now to the drawing in which like characters of referencedesignate similar parts in the various views, In designates a base uponwhich preferably an electric motor II is secured 30 by screws l2. Theshaft of the motor is equipped with a grinding wheel I3 the same beingclamped on the shaft between a collar l4 and a washer E5, the latterbeing held in place by a nut 55 which is threaded on the end of theshaft. 55 The periphery H of the grinding wheel is concave or dishedfrom edge to edge as best shown in Figure 1. p

A transparent casing 18 is removably supported on the base by means ofspring clips l9 which engage in openings 20 in the casing as best shownin Figure 3. The casing houses the motor and the grinding wheel andcollects the sawdust while at the same time permitting the sharpeningoperation to be viewed by the operator.

A downwardly directed shield 2| is secured at the upper end to the frontof the casing by a bolt 22. The shield slopes downwardly toward thebottom of the grinding wheel and prevents sawdust from following thewheel around in the direction of rotation and consequently the clearvision of the sharpening operation is not obstructed at any time.

The pencil holder comprises a pair of aligned tubes 23 and 24 which arecarried by respective plates 25 and 26 that are adjustably clampedagainst the inner face and the outer face of the front wall of thecasing by bolts 2! and 28 which pass through vertical slots 29 and 30formed in the front wall of the casing.

A guide tube 3|, having a flared outer end 32, is axially received inthe aligned tubes 23 and 24. The guide tube 3! positions the pencil 33to extend tangentially with respect to the periphery of the grindingwheel and also centers the pencil on the periphery midway between theside edges of the grinding wheel. A leaf spring 34 is secured to the topof the casing by a bolt 35 and extends downwardly into the space betweenthe inner end of the guide tube 3| and the grinding wheel l3. Thisspring exerts pressure upon the pencil during the sharpening operation.

An electric lamp 36 is mounted on a housing 31 which is placed over themotor H and is secured to the base by screws 38. The lamp and the motorare energized from the same supply wires 39 so tha when the motor isrunning the lamp will be lit. A switch 40 is disposed on the base andcontrols the supply of current to the motor and to the lamp.

While a motor has been illustrated as furnishing the driving power forthe grinding wheel the motor may be dispensed with in some instances andthe grinding wheel shaft may be hand operated by any well known type ofstep-up gear mechanism.

By virtue of the concave grinding surface, and by virtue of the guidetubes positioning the pencil tangentially to this surface and centeredthereon, the pencil will be sharpened to present a wood surface whichmay be said to be a surface traced by a moving arcuate line passingthrough a fixed vertex. Consequently there will be more wood at thejuncture of the lead than ordinarily is found where the pencil issharpened to a conical point and in practice it is found that thesharpened end of the pencil is shorter by virtue of this novel surfacecontour than ordinarily is the case where the pencil is sharpened to aconical point.

By adjusting the guide tube 3| vertically in the vertical slot 29' theuser may vary the position of the pencil with respect to the grindingwheel at will and thus accomplish the dual function of regulating thesharpened point to a stub point, and also permitting adjustment of thetube to compensate for any wear on the wheel.

From the above description it is thought that the construction andoperation of the invention will be fully understood without furtherexplanation.

What is claimed is:

A pencil sharpener comprising a base, a revolvable grinding wheelmounted thereon and having a concave periphery, a transparent casingfashioned with a pencil receiving slot and secured to the base andhousing said wheel, a pair of aligned tubes clamped to said casing aboutsaid slot and vertically adjustable on said casing, and a guide tubeextending through said first mentioned tubes and adjustable therewith toposition a pencil tangentially to the wheel and within said concaveperiphery, said casing coacting with said tubes to permit the end of apencil to be viewed and adjusted into operating engagement with saidwheel from the exterior of said casing.

HOWARD W. JENKINS.

